An explicit immunogenetic model of gastrointestinal nematode infection in sheep

Gastrointestinal nematodes are a global cause of disease and death in humans, wildlife and livestock. Livestock infection has historically been controlled with anthelmintic drugs, but the development of resistance means that alternative controls are needed. The most promising alternatives are vaccination, nutritional supplementation and selective breeding, all of which act by enhancing the immune response. Currently, control planning is hampered by reliance on the faecal egg count (FEC), which suffers from low accuracy and a nonlinear and indirect relationship with infection intensity and host immune responses. We address this gap by using extensive parasitological, immunological and genetic data on the sheep–Teladorsagia circumcincta interaction to create an immunologically explicit model of infection dynamics in a sheep flock that links host genetic variation with variation in the two key immune responses to predict the observed parasitological measures. Using our model, we show that the immune responses are highly heritable and by comparing selective breeding based on low FECs versus high plasma IgA responses, we show that the immune markers are a much improved measure of host resistance. In summary, we have created a model of host–parasite infections that explicitly captures the development of the adaptive immune response and show that by integrating genetic, immunological and parasitological understanding we can identify new immune-based markers for diagnosis and control.     

A comparison of reactive plasma pre-treatments on PET substrates by Cu and Ti pulsed-DC and HIPIMS discharges

PET web samples have been treated by magnetically enhanced glow discharges powered using either medium frequency pulse direct current (p-DC) or low frequency high power pulse (HIPIMS) sources. The plasma pre-treatment processes were carried out in an Ar–O₂ atmosphere using either Cu or Ti sputter targets. XPS, AFM and sessile drop water contact angle measurements have been employed to examine changes in surface chemistry and morphology for different pre-treatment process parameters. Deposition of metal oxide onto the PET surface is observed as a result of the sputter magnetron-based glow discharge web treatment. Using the Cu target, both the p-DC and HIPIMS processes result in the formation of a thin CuO layer (with a thickness between 1 and 11 nm) being deposited onto the PET surface. Employing the Ti target, both p-DC and HIPIMS processes give rise to a much lower concentration of Ti (< 5 at.%), in the form of TiO₂ on the PET treated surface. The TiO₂ is probably distributed as an island-like distribution covering the PET surface. Presence of Cu and Ti oxide constituents on the treated PET is beneficial in aiding the adhesion but alone (i.e. without oxygen plasma activation) is not enough to provide very high levels of hydrophilicity as is clear from sessile drop water contact angle measurements on aged samples. Exposure to the plasma treatments leads to a small amount of roughening of the substrate surface, but the average surface roughness in all cases is below 2.5 nm. The PET structure at the interface with a coating is mostly or wholly preserved. The oxygen plasma treatment, metal oxide deposition and surface roughening resulting from the HIPIMS and p-DC treatments will promote adhesion to any subsequent thin film that is deposited immediately following the plasma treatment.     

Modelling the Material Flow and Web Tension in the Vertical Form–Fill–Seal Packaging Process

Vertical form–fill–seal (VFFS) machines are widely used to form bags for packaging products such as confectionary and snack food. One critical component of the machine is the forming shoulder, which needs to manipulate, without damage, the packaging material from a flat state into a tube. Some models of the geometry of the shoulder are available and have been used to help with its design and manufacture. However, there currently exists no theoretical basis for determining the geometry of the forming shoulder needed to process particular packaging materials. This paper investigates the application of Euler's theory for material flow around cylinders to the case of forming shoulders used in vertical form–fill–seal systems. It is shown that the theory is indeed applicable, and an inequality relation between the measured coefficient of friction of the material and the forming shoulder parameters is established. It is further shown how this can be used to direct the design of a forming shoulder for a particular application. Copyright © 2011 John Wiley & Sons, Ltd.     

The relative impact of work-related stress, life stress and driving environment stress on driving outcomes

Previous research has shown the association between stress and crash involvement. The impact of stress on road safety may also be mediated by behaviours including cognitive lapses, errors, and intentional traffic violations. This study aimed to provide a further understanding of the impact that stress from different sources may have upon driving behaviour and road safety. It is asserted that both stress extraneous to the driving environment and stress directly elicited by driving must be considered part of a dynamic system that may have a negative impact on driving behaviours. Two hundred and forty-seven public sector employees from Queensland, Australia, completed self-report measures examining demographics, subjective work-related stress, daily hassles, and aspects of general mental health. Additionally, the Driver Behaviour Questionnaire (DBQ) and the Driver Stress Inventory (DSI) were administered. All participants drove for work purposes regularly, however the study did not specifically focus on full-time professional drivers. Confirmatory factor analysis of the predictor variables revealed three factors: DSI negative affect; DSI risk taking; and extraneous influences (daily hassles, work-related stress, and general mental health). Moderate intercorrelations were found between each of these factors confirming the ‘spillover’ effect. That is, driver stress is reciprocally related to stress in other domains including work and domestic life. Structural equation modelling (SEM) showed that the DSI negative affect factor influenced both lapses and errors, whereas the DSI risk-taking factor was the strongest influence on violations. The SEMs also confirmed that daily hassles extraneous to the driving environment may influence DBQ lapses and violations independently. Accordingly, interventions may be developed to increase driver awareness of the dangers of excessive emotional responses to both driving events and daily hassles (e.g. driving fast to ‘blow off steam’ after an argument). They may also train more effective strategies for self-regulation of emotion and coping when encountering stressful situations on the road.     

Participatory ergonomics: development of an employee assessment questionnaire

Despite being essential to the success of participatory ergonomics (PEs) programs, there are currently no known quantitative measures that capture the employees’ perspective of PE program effectiveness. The present study addresses this need through the development of the Employee Perceptions of Participatory Ergonomics Questionnaire (EPPEQ). The questionnaire is designed to assess five key components that are based on a review of the available literature: Employee Involvement, Knowledge Base, Managerial Support, Employee Support, and Strain related to ergonomic changes. In Phase 1, a sample of employees and ergonomists working at a manufacturing plant was used to develop and test an initial set of items. In Phase 2, data was collected from a nation-wide sample of employees representing a wide range of jobs and organizations to cross-validate the results from Phase 1. Phase 2 results indicate that the five EPPEQ subscales demonstrate sound convergent validity and are also correlated with traditional indicators of PE program success. Implications and uses of the EPPEQ are discussed.     

Plasma-based processes and thin film equipment for nano-scale device fabrication

Plasma-based thin film equipment and processes have been widely used for micro-electronics, information storage sensors, and energy harvest/storage devices. To achieve higher package density, large storage capacity, and to meet other specific stringent design criteria, the film layer thickness is often reduced to a few nanometers or even to a few angstroms, while the device dimension has been shrinking to sub-micrometer scales. As the material thickness (h) approaches atomic dimension and the device dimension (w × d) approaches a few tens of nanometers, thin film layer uniformity and inter-layer mixing, as well as device edge damage control are crucial for its performance and reliability. In this review paper, we will discuss briefly vacuum and plasma aspects, followed by a detailed review on various plasma-based thin film deposition and removal techniques. The deposition methods discussed here include magnetron sputtering, ion beam deposition (IBD), and plasma enhanced chemical vapor deposition (PECVD). We focus on the advantages and disadvantages of various hardware configurations and how to achieve uniform film growth over large area with minimized interlayer mixing for any specific process. The device patterning aspects cover ion beam etching (IBE), reactive ion etching (RIE), and various techniques for end-point detection of etching processes. We discuss how the definition technique affects edge damage, profile, and dimension (w × d) control, as well as post-definition corrosion behavior. Some specific examples will be presented to highlight how the physical principles can be used in practice for film/device property control.     

Absorption of L-carnosine, L-methionine, and L-methionylglycine by isolated sheep ruminal and omasal epithelial tissue

The absorption of carnosine, methionine, and methionylglycine (using 35S-methionine and 35S-methionylglycine as representative markers) across ruminal and omasal epithelia collected from four (carnosine) and seven sheep (methionine and methionylglycine) were studied using parabiotic chambers that were repeatedly sampled over a 240-min incubation. The quantity of all substrates transferred was linearly (P < .01) dependent on initial substrate concentration and time. More (P < .01) carnosine, methionine, and methionylglycine was transferred across omasal than across ruminal epithelia. Carnosine was absorbed across both tissues without hydrolysis. Methionylglycine was transferred intact across both tissues. A greater (P < .01) quantity was hydrolyzed by omasal than by ruminal epithelia, after 240 min of incubation. Greater (P < .06) quantities of methionine and methionylglycine accumulated in ruminal tissue after 240 min. Total absorption of methionine and methionylglycine did not differ within tissues, but total absorption of both substrates was greater (P < .01) by omasal tissues. There was little evidence for saturable absorption. These results indicate that omasal epithelial tissue possesses a greater ability to absorb both free and peptide-bound amino acids than does ruminal epithelial tissues.     

Eukaryotic and prokaryotic cell functions required for invasion of Staphylococcus aureus into bovine mammary epithelial cells

OBJECTIVE: To investigate patterns of attendance and non-attendance at National Health Service antenatal classes of first-time mothers in the indigenous white population of a large northern city of the UK. DESIGN: Survey using questionnaires, and selected participants were then given an in-depth interview. SETTING: Five maternity wards in two large northern hospitals in the UK. In-depth interviews took place in the respondents' homes. PARTICIPANTS: Fifty newly delivered women were surveyed of whom 18 took part in the follow-up interviews. FINDINGS: There was a clear hierarchy in attendance and non-attendance based on social class, with middle class women being the most regular attenders, closely followed by older, married, working class women. However, overall social class differences were found to be accounted for by the overwhelming non attendance of young, unmarried, working class women. Older, married, working class women were found to have attendance patterns which were close to their middle class counterparts, and what differences there were seemed to be based on material factors. KEY CONCLUSIONS: The majority of women felt that antenatal classes were too technical and did not address emotional and psychological issues. However, young, single unmarried women perceived the classes most negatively. If midwives are to attract such young women, their fears and their need for peer support will have to be recognised.